Custom MHC-peptides Tetramer Service
MHC tetramer is a complex of 4 MHC molecules associated with loaded peptide, which is bound to a fluorescently labeled streptavidin molecule. Monomeric MHC molecule is loaded with its cognate peptide, and biotin is linked to the complex at a site far removed from the T-cell recognition site. The monomeric MHC-peptide complexes bind to streptavidin, which further tightly binds biotin at 4 separate sites, thus making a tetrameric complex, the MHC tetramer.
MHC tetramer technology is an innovative method of directly staining freshly isolated antigen-specific T-cells, which has greatly enhanced our ability to assess cellular dynamics during an immune response. Joining multiple copies of the MHC/antigen complex into a single probe, tetramer technology, resolves the difficulties presented by the low affinity of MHC molecule to the specific T cell.
Creative Peptides is offering MHC tetramer synthesis with a set of peptide sequences customized by customers now. Here is a list of available alleles that Creative Peptides can provide. Currently two choices of fluorochrome labeling are available based on customer’s request: phycoerythrin (PE) or allophycocyanin (APC). Creative Peptides also provides clinical grade tetramer for our clients. These highly purified products can be used in immunotherapy trials.
Our MHC-peptide tetramers include:
• Class I MHC tetramers for antigen-specific CD8+ T cells detection ex vivo
• Class II MHC tetramers for antigen-specific CD4+ T cells detection ex vivo
• Fluorophore-labeledtetramers for flow cytometry or fluorescence microscopy
• CD1d tetramers for detection of natural killer T (NKT) cells
• Human alleles
• Non-Human alleles
• Negative tetramers as a negative control for Class I Tetramer staining
Every step of peptide synthesis is subject to Creative Peptides’ stringent quality control. Typical delivery specifications include:
• HPLC chromatogram
• Mass spec analysis
• Synthesis report
• Certificate of Analyses
MHC tetramer is an innovative product of directly staining freshly isolated antigen-specific T-cells. The isolated cells can be cultured, multiplied and stored for further study use. In the production of tetramers, the MHC heavy chain protein, the light chain protein and the epitopic peptide are refolded into MHC complex in vitro. The successfully refolded monomers are purified by gel-filtration and then biotinylated and stored at –80 °. The biotinylated monomers are bound to fluorescent- labeled streptavidin, generally APC or PE before use. Streptavidin has 4 available binding sites for biotin, thus making a tetramer of MHC molecules with bound peptides. Details of the protocols can be found at NIH Tetramer Core Facility's website.
Note: Custom tetramers may differ significantly in refolding, stability and staining of T cells. It is much dependent on the MHC alleles and the binding affinity of a specific peptide to the MHC molecule. Creative Peptides recommends testing of every new batch of MHC tetramers with positive and negative control cells by titration of the tetramer reagent. Tetramers should be stored at 4°C and retested after long-term storage.
1. Constantin, C. M., Bonney, E. E., Altman, J. D., & Strickland, O. L. (2002). Major histocompatibility complex (MHC) tetramer technology: an evaluation. Biol Res Nurs, 4(2), 115-127.
2. Davis, M. M., Altman, J. D., & Newell, E. W. (2011). Interrogating the repertoire: broadening the scope of peptide-MHC multimer analysis. Nat Rev Immunol, 11(8), 551-558.